From: Ajay Garg <ajaygargnsit@gmail.com>
To: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Ajay Garg <ajaygargnsit@gmail.com>
Subject: [PATCH] tty: vt: keyboard: do not copy an extra-byte in copy_to_user
Date: Sat, 6 Nov 2021 14:50:40 +0530 [thread overview]
Message-ID: <20211106092041.43745-1-ajaygargnsit@gmail.com> (raw)
Both (statically-allocated) "user_kdgkb->kb_string" and
(dynamically-allocated) "kbs" are of length "len", so we must
not copy more than "len" bytes.
Signed-off-by: Ajay Garg <ajaygargnsit@gmail.com>
---
drivers/tty/vt/keyboard.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
index c7fbbcdcc346..dfef7de8a057 100644
--- a/drivers/tty/vt/keyboard.c
+++ b/drivers/tty/vt/keyboard.c
@@ -2070,7 +2070,7 @@ int vt_do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
len = strlcpy(kbs, func_table[kb_func] ? : "", len);
spin_unlock_irqrestore(&func_buf_lock, flags);
- ret = copy_to_user(user_kdgkb->kb_string, kbs, len + 1) ?
+ ret = copy_to_user(user_kdgkb->kb_string, kbs, len) ?
-EFAULT : 0;
break;
--
2.30.2
next reply other threads:[~2021-11-06 9:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-06 9:20 Ajay Garg [this message]
2021-11-06 11:23 ` [PATCH] tty: vt: keyboard: do not copy an extra-byte in copy_to_user Pavel Skripkin
2021-11-06 12:05 ` Ajay Garg
2021-11-06 12:39 ` Pavel Skripkin
2021-11-06 16:40 ` David Laight
2021-11-06 19:20 ` Ajay Garg
2021-11-06 19:46 ` Ajay Garg
2021-11-06 20:18 ` Pavel Skripkin
2021-11-06 20:30 ` Ajay Garg
2021-11-06 20:34 ` Pavel Skripkin
2021-11-06 20:44 ` Ajay Garg
2021-11-06 20:48 ` Pavel Skripkin
2021-11-08 8:59 ` Ajay Garg
2021-11-08 11:58 ` Pavel Skripkin
2021-11-08 12:12 ` Ajay Garg
2021-11-10 5:22 ` Jiri Slaby
2021-11-10 7:37 ` Pavel Skripkin
2021-11-10 8:57 ` Ajay Garg
2021-11-10 9:06 ` Greg KH
2021-11-10 9:32 ` Ajay Garg
2021-11-06 19:56 ` Pavel Skripkin
2021-11-06 20:07 ` Ajay Garg
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211106092041.43745-1-ajaygargnsit@gmail.com \
--to=ajaygargnsit@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox